Call transfer for an integrated wireline and wireless service using a temporary directory number

ABSTRACT

The present invention relates to a communication environment where calls are established with a single mobile terminal through either a wireless network or the public switched telephone network (PSTN) via a terminal adaptor, which is capable of wirelessly communicating with the mobile terminal. As such, the mobile terminal may facilitate traditional cellular calls via the wireless network, or traditional PSTN calls via the terminal adaptor. A temporary directory number for the mobile terminal is provided by the wireless network and used for facilitating calls via the wireless network. The terminal adaptor, supporting telephony switch, and wireless network will cooperate to transfer calls to the wireless network as necessary or desired.

This application claims the benefit of U.S. provisional patentapplication Ser. No. 60/472,277, filed May 21, 2003, the disclosure ofwhich is hereby incorporated by reference in its entirety.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to concurrently filed U.S. patentapplication Ser. No. ______ entitled CALL TRANSFER FOR AN INTEGRATEDWIRELINE AND WIRELESS SERVICE USING A TEMPORARY DIRECTORY NUMBER,currently pending, the disclosure of which is incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates to mobile communications, and inparticular to allowing a single mobile terminal to transition fromcommunicating over the public switched telephone network tocommunicating over a wireless network.

BACKGROUND OF THE INVENTION

Today's telephony users generally have at least one wireline-basedtelephone receiving services through the public switched telephonenetwork (PSTN) and a mobile telephone receiving services through acellular network. These wireline and mobile telephones are incompatible,and are thus incapable of facilitating communications over both thecellular and public switched networks. As such, telephony users mustjuggle multiple telephones, using one telephone to make and receivecalls via the cellular network, and another to make and receive callsvia the PSTN. Given the multiple telephones, callers must keep track ofmultiple directory numbers. Additionally, incoming calls are generallyfree through the service providers of the PSTN, while cellular serviceproviders charge for such incoming calls. Accordingly, there is a needfor a technique to allow a single telephony device to interface withboth the cellular network and the PSTN in an effective and efficientmanner. There is also a need to provide an efficient transfer mechanismto transition a call through the PSTN to a call through the cellularnetwork, when communications via the PSTN are no longer possible.

SUMMARY OF THE INVENTION

The present invention relates to a communication environment where callsare established with a single mobile terminal through either a wirelessnetwork or the public switched telephone network (PSTN) via a terminaladaptor, which is capable of wirelessly communicating with the mobileterminal. As such, the mobile terminal may facilitate traditionalcellular calls via the wireless network, or traditional PSTN calls viathe terminal adaptor. The terminal adaptor and mobile terminalcommunicate via a local wireless interface, and as such, communicationsvia the PSTN through the terminal adaptor are only possible within alimited communication zone supported by the terminal adaptor. When themobile terminal is involved in a call and within the communication zoneof the terminal adaptor, calls are facilitated via the wirelessinterface with the terminal adaptor. As the mobile terminal approachesthe outer limits of the communication zone, the terminal adaptor willdetect a decrease in its ability to facilitate effective communicationswith the mobile terminal and trigger the supporting telephony switch toeffectively transfer the call to the mobile terminal through thewireless network, as well as register with the wireless network, ifregistration has not already taken place. Preferably, the mobileterminal is associated with a primary directory number that isassociated with the PSTN. A temporary directory number for the mobileterminal is provided by the wireless network and is used forfacilitating incoming calls, outgoing calls, and service transitionsbetween the PSTN and wireless network.

The mobile terminal will simply answer the new incoming call made to thetemporary directory number associated with the mobile terminal whenserved by the wireless network. This effects a transition from the PSTNconnection to the wireless connection. The terminal adaptor may interactwith the supporting telephony switch to assist in establishing the call,as well as effecting the transition. The transition may be implementedby using a traditional call transfer technique, the technique used whenestablishing a three-way call, or any other technique for allowing atelephony switch to change the telephony connection from one directorynumber to another.

Those skilled in the art will appreciate the scope of the presentinvention and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a block representation of a communication environmentaccording to one embodiment of the present invention.

FIGS. 2A-2C provide a communication call flow diagram wherein a mobileterminal moves out of range of PSTN communications via a terminaladaptor.

FIG. 3 is a block representation of a terminal adaptor according to oneembodiment of the present invention.

FIG. 4 is a block representation of a service node according to oneembodiment of the present invention.

FIG. 5 is a block representation of a mobile terminal according to oneembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the invention and illustratethe best mode of practicing the invention. Upon reading the followingdescription in light of the accompanying drawing figures, those skilledin the art will understand the concepts of the invention and willrecognize applications of these concepts not particularly addressedherein. It should be understood that these concepts and applicationsfall within the scope of the disclosure and the accompanying claims.

The present invention relates to providing a mobile terminal that iscapable of communication via a cellular-based wireless network, as wellas via the public switched telephone network (PSTN) through a terminaladaptor. The terminal adaptor is coupled to the PSTN in traditionalfashion, and communicates wirelessly with the mobile terminal usinglocal wireless access technology, such as traditional analog and digitalcordless technologies, 802.11 wireless local area network technologies,and Bluetooth technology. The mobile terminal is preferably associatedwith a primary directory number for PSTN access, and is associated witha temporary directory number for cellular access. Communications withthe wireless network can use any available cellular access technology,such as time division multiple access (TDM), code division multipleaccess (CDMA), and orthogonal frequency division multiple access (OFDM).

In addition to connecting to the PSTN and providing wireless access forthe mobile terminal, the terminal adaptor may have a data interfacethrough which the terminal adaptor can communicate with a service node,which controls the routing of incoming calls directed to the mobileterminal. The terminal adaptor will determine when the mobile terminalis within a zone in which communication via the local wireless accesstechnology is possible, and provide information to the service nodebearing on whether the mobile terminal is within or outside of the zone.The service node will take this information and direct incoming calls tothe PSTN directory number for the mobile terminal associated with theterminal adaptor when the mobile terminal is within the zone, and directcalls to the temporary directory number associated with the wirelessnetwork when the mobile terminal is outside of the zone. As such,incoming calls are either routed through the wireless network or throughthe PSTN to the terminal adaptor, depending on whether the terminaladaptor can effectively communicate with the mobile terminal.

Regardless of whether a PSTN call is originated from or received by themobile terminal via the terminal adaptor, the present invention providesfor transferring the connection for the call such that it isreestablished through the wireless network when the mobile terminalmoves outside of the zone of the terminal adaptor. Preferably, theterminal adaptor or mobile terminal will monitor the quality of the callor other indicia indicative of the ability of the terminal adaptor toeffectively communicate with the mobile terminal, to determine whetheror not the mobile terminal is within or outside of the zone. When themobile terminal leaves the zone, the terminal adaptor will initiate atransition of the call to the temporary directory number for the mobileterminal, which is associated with the wireless network. Preferably, theterminal adaptor will trigger the telephony switch to transfer the call,and once the connection through the wireless network is established,drop the connection to the terminal adaptor. Those skilled in the artwill recognize numerous techniques for triggering the servicingtelephony switch to initiate a call to the mobile terminal via thewireless network directory number, such as in traditional call transfer,establishing a three-way call, or simply establishing separate telephonyconnections. In addition to the telephone line connecting to theterminal adaptor, the call can alternatively be routed, using standardpacket telephony, via a data network and data access network to theterminal adaptor, first going through a telephony gateway connected tothe telephony switch. The following description will enable thoseskilled in the art to practice the invention. An overview of anexemplary network architecture is provided prior to delving into theoperation of the preferred embodiments of the present invention.

With reference to FIG. 1, a communication environment 10 allows a mobileterminal 12 to communicate via a wireline switch 14 through a terminaladaptor 16, as well as via a wireless switch 18 through a cellularaccess network 20. The wireline and wireless switches 14, 18 may beoperatively coupled via one or more portions of the public switchedtelephone networks (PSTN) 22, and may be based on time-divisionmultiplex (TDM) or packet technology. The wireline switch 14 may also beembodied in a private branch exchange (PBX).

The terminal adapter 16 interfaces with a telephone line connected tothe wireline switch 14, and facilitates wireless communications with themobile terminal 12. For an incoming or outgoing call via the telephoneline, the terminal adaptor 16 will provide a circuit-switched interfaceto the telephone line and a wireless interface to the mobile terminal12, wherein the mobile terminal 12 may operate similarly to atraditional cordless telephone.

The wireless interface provided by the terminal adaptor 16 will have alimited range, and as such, will provide a terminal adapter zone 24,which defines an area or range in which communications between theterminal adaptor 16 and the mobile terminal 12 are possible. Theterminal adaptor 16, through any of a variety of possible techniques,will determine whether the mobile terminal 12 is within the terminaladapter zone 24, and provide information bearing on the presence of themobile terminal 12 through a data access network 26 and data network 28to a service node 30, directly or via customer premise equipment (notshown). The customer premise equipment may be a cable modem, DigitalSubscriber Line (DSL) modem, Integrated Services Digital Network (ISDN)modem, or like communication terminal that provides access to the dataaccess network 26 via the corresponding cable network, DigitalSubscriber Line (DSL) network, or IDSN forming the data access network26.

The service node 30 is configured to interact with the wireline switch14 via a network and any necessary translation devices (not shown) toassist in routing incoming calls directed to the mobile terminal 12.Preferably, communications with the wireline switch 14 use IntelligentNetwork (IN) signaling, and communications with the terminal adaptor 16are implemented using the Session Initiation Protocol (SIP); however,those skilled in the art will recognize the applicability of alternativesignaling technologies and protocols. Alternatively, the service nodefunctionality may be implemented in the wireline switch 14.

In the illustrated embodiment, assume a directory number DN1 isprovisioned for the telephony line connected to the terminal adaptor 16,and thus, calls to directory number DN1 will be directed to the mobileterminal 12 via the terminal adaptor 16 when the mobile terminal 12 iswithin the terminal adaptor zone 24, or ultimately via the cellularaccess network 20 when the mobile terminal 12 is not within the terminaladaptor zone 24 or as desired by the user. Techniques for routing thecall via the cellular access network 20 are described further below.

Incoming calls using the PSTN directory number DN1 are routed to thewireline switch 14, which is provisioned to access the service node 30to determine how to further route the call for termination. The servicenode 30 will receive a message from the wireline switch 14 identifyingthe directory number associated with the called party for the incomingcall. From the directory number, the service node 30 will recognize thatthe directory number DN1 is associated with the mobile terminal 12. Assuch, the service node 30 will determine whether the mobile terminal 12is within the terminal adapter zone 24 of the terminal adaptor 16 basedon a query to the terminal adaptor 16 or information provided by theterminal adaptor 16 on a periodic basis. If the mobile terminal 12 iswithin the terminal adapter zone 24, the service node 30 will send amessage to the wireline switch 14 directing the wireline switch 14 toroute the incoming call to the mobile terminal 12 via the terminaladaptor 16 using the PSTN directory number DN1. If the mobile terminal12 is not within the terminal adapter zone 24, the service node 30 willinstruct the wireline switch 14 to route the call to the mobile terminal12 through the cellular access network 20 using a temporary directorynumber. The temporary directory number is retrieved from the wirelessswitch 18 or an associated visiting location register (VLR) 32 via asignaling network 36, directly or indirectly via a home locationregister (HLR) 34 associated with the wireline switch 14.

The VLR 32 generally operates in traditional fashion, and may bespecially configured to provide or access the temporary directory numberfrom the wireless switch 18 currently servicing the mobile terminal 12.The HLR 34, although associated with the wireline switch 14, operates inan analogous fashion to a wireless-based HLR 34. In operation, the HLR34 and VLR 32 cooperate to provide the temporary directory number to theservice node 30. The service node 30 will provide the temporarydirectory number to the wireline switch 14, such that the incoming callcan be directed to the wireless switch 18, if the mobile terminal 12 isnot within the terminal adaptor zone 24 or as directed by the user. Foradditional information related to routing incoming calls via theterminal adapter 16 or the wireless network 18, please see U.S.application Ser. No. 10/409,280 filed Apr. 8, 2003, U.S. applicationSer. No. 10/409,290 filed Apr. 8, 2003, U.S. application Ser. No.10/410,949 filed Apr. 10, 2003, and U.S. application Ser. No. 10/411,159filed Apr. 10, 2003, the disclosures of which are incorporated herein byreference in their entireties.

The terminal adaptor 16 may support multiple mobile terminals 12, whichare capable of establishing telephony communications via the wirelessswitch 18 or via the wireline switch 14 through the terminal adaptor 16.Accordingly, the terminal adaptor 16 may be able to keep track of themultiple mobile terminals 12 to determine whether they are presentwithin the terminal adapter zone 24 and report such information to theservice node 30 periodically or when attempting to terminate an incomingcall. Since the terminal adaptor 16 can communicate via the data accessnetwork 26 in addition to communicating over the telephone line, voiceover packet communications are possible between the wireline switch 14and the terminal adaptor 16.

Regardless of the originating party to a call, when the user engaged inthe call takes the mobile terminal 12 outside of the terminal adapterzone 24, the ability of the terminal adaptor 16 to effectivelycommunicate with the mobile terminal 12 will diminish, and ultimatelystop. Accordingly, the terminal adaptor 16 (or the mobile terminal 12)will directly or indirectly monitor metrics indicative of its ability tomaintain communications with the mobile terminal 12. The metrics thatthe terminal adaptor 16 (or the mobile terminal 12) may monitor couldinclude actual bit error rates, signal strengths, signal-to-interferenceratios, or any other indication bearing on the ability to provide aminimum level of quality. Once the metric measurement has dropped belowa minimum threshold, which is indicative of the mobile terminal 12leaving the terminal adapter zone 24, the terminal adaptor 16 willsignal the wireline switch 14 to initiate a call to the mobile terminal12 using a temporary directory number (TDN), transfer the call to thenew connection established via the wireless switch 18, and drop theconnection via the terminal adaptor 16.

Preferably, the terminal adaptor 16 will provide the temporary directorynumber to the wireline switch 14 through signaling. Typically, a flashsignal (a quick onhook/offhook transition) may be sent to the wirelineswitch 14 to signal the desire to transfer the call to another number.The terminal adaptor 16 may be configured to automatically provide theflash signal when it determines that the call must be transferredthrough the wireless switch 18. Further, the terminal adaptor 16 may beconfigured to actually dial the temporary directory number, and have thewireline switch 14 transfer the user's ongoing call from the PSTNdirectory number DN1 to the temporary directory number. Those skilled inthe art will recognize various other techniques for switching from thePSTN call to a wireless call.

Notably, just prior to or during transfer, the terminal adaptor 16 mayinsert tones or other signals into the voice path to alert both partiesinvolved in the call that the transfer will take place. Further, theterminal adaptor 16 may be configured to receive a signal from themobile terminal 12 to proactively request a transfer of the call to thewireless directory number. As such, the user may simply press a key onthe mobile terminal 12, which sends a signal capable of being detectedby the terminal adaptor 16. Upon receipt of the signal, the terminaladaptor 16 will effect the transfer to the wireless directory number.

Continuing with FIG. 1, a high level process for accessing a temporarydirectory number and facilitating a transfer of a call to the mobileterminal 12 from the terminal adaptor 16 through the to the cellularaccess network 20 is provided. Initially, an incoming call intended forthe mobile terminal 12 using directory number DN1 is connected to theterminal adaptor 16, which will facilitate bidirectional communicationsto support the call with the mobile terminal 12 (step A). At some point,either before the call, during the call, or when either the mobileterminal 12 or terminal adaptor 16 detects that the mobile terminal 12is leaving the terminal adaptor zone 24, the mobile terminal 12 willinitiate cellular registration via the cellular access network 20 (stepB). The cellular registration may take place while the call via theterminal adaptor 16 is in progress, and as such, the mobile terminal 12must be configured to facilitate wireless communications with theterminal adaptor 16 as well as communications with the cellular accessnetwork 20. Upon registration with the cellular access network 20, themobile terminal 12 is assigned the temporary directory number by thewireless switch 18 or other appropriate entity, including the VLR 32.The temporary directory number must be provided to the wireline switch14 to establish a connection with the mobile terminal 12 via thewireless switch 18 and the associated cellular access network 20.

To obtain the temporary directory number for the wireline switch 14, theterminal adaptor 16 will sense the need to transfer the call via thecellular access network 20 to the mobile terminal 12 and send a requestto retrieve the temporary directory number to the service node 30 viathe data access network 26 and data network 28 (step C). The servicenode 30 will then take the necessary steps to access the temporarydirectory number, directly or indirectly from the VLR 32 or wirelessswitch 18, depending on where the temporary directory number is storedin association with the registration for the mobile terminal 12. In theillustrated embodiment, the service node 30 will send a request for thetemporary directory number to the HLR 34 (step D), which will send arequest to the appropriate VLR 32 (step E), which is associated with thecellular access network 20 currently servicing the mobile terminal 12.If the VLR 32 does not have the temporary directory number for themobile terminal 12, a request may be made of the wireless switch 18(step F) or other entity having the temporary directory number. Assumingthe wireless switch 18 keeps track of the temporary directory number,the wireless switch 18 will respond to the request from the VLR 32 byreturning the temporary directory number (step G). The VLR 32 will thenforward the temporary directory number to the HLR 34 (step H), whichwill in turn forward the temporary directory number to the service node30 (step I).

Once the service node 30 obtains the temporary directory number, it willsend it to the terminal adaptor 16 (step J), which will send thetemporary directory number to the wireline switch 14 (step K) toinitiate transferring the call through the cellular access network 20from the terminal adaptor 16. The wireline switch 14 will receive therequest with the temporary directory number and initiate a connectionwith the mobile terminal 12 via the wireless switch 18 and cellularaccess network 20 (step L). Once this connection is established, theincoming call is connected through the wireless switch 18 and cellularaccess network 20, while the connection from the wireline switch 14 tothe terminal adaptor 16 is dropped.

An exemplary communication flow for the above process is provided inFIGS. 2A-2C. Initially, assume the terminal adaptor 16 provides a pagingsignal within the terminal adaptor zone 24 (step 100), and the mobileterminal 12 receives the paging signal and responds with an appropriateresponse, such as a Hello message (step 102). At this point, theterminal adaptor 16 recognizes that the mobile terminal 12 is within theterminal adaptor zone 24. Upon receiving an incoming call for the mobileterminal 12, an Integrated Services User Protocol (ISUP) Initial AddressMessage (IAM) is received via the PSTN 22, and identifies the directorynumber DN1 associated with the mobile terminal 12. The ISUP IAM isreceived by the wireline switch 14 (step 104), which is provisioned toobtain routing instructions from the service node 30 using anIntelligent Network (IN) Termination Attempt Trigger (TAT), which willtypically identify the directory numbers for the caller and called party(DN0 and DN1) (step 106).

The service node 30 may receive periodic updates from the terminaladaptor 16 identifying whether or not the mobile terminal 12 is withinthe terminal adaptor zone 24. Alternatively, the service node 30 may beconfigured to query the terminal adaptor 16 upon receiving the IN TAT todetermine whether the mobile terminal 12 is within the terminal adaptorzone 24. In the illustrated embodiment, the service node 30 uses theSession Initiation Protocol (SIP) to send a SIP Invite message to theterminal adaptor 16 to effectively determine whether the mobile terminal12 is within the terminal adaptor zone 24 (step 108). The SIP Invite isintended to establish a session with the terminal adaptor 16, but theterminal adaptor 16 will recognize that a connection via the wirelineswitch 14 is capable and respond with a SIP 380 Alternate Servicemessage instructing the service node 30 to route the call via the PSTNthrough the wireline switch 14 (step 110). The service node 30 willreceive the SIP 380 Alternate Service message, determine that the callshould be routed through the wireline switch 14 and the terminal adaptor16, and as such, send an IN Continue message to the wireline switch 14(step 112), which will send a Ringing signal to the terminal adaptor 16(step 114).

The terminal adaptor 16 will then take the necessary steps to cause themobile terminal 12 to ring (step 116), as well as send an ISUP AddressComplete Message (ACM) back to the wireline switch 14 (step 118), whichwill forward the ISUP ACM back to the PSTN 22 (step 120) to effectivelyalert the telephony switch supporting the calling terminal. When themobile terminal 12 is answered (step 122), the terminal adaptor willsend an ISUP Answer Message (ANM) to the wireline switch 14 (step 124),which will forward the ISUP ANM through the PSTN 22 toward the telephonyswitch of the caller (step 126) to establish a TDM connection betweenthe caller's telephony switch and the wireline switch 14 (step 128). Thewireline switch 14 and the terminal adaptor 16 will establish an analogconnection over the telephony line (step 130), and the terminal adaptor16 and the mobile terminal 12 will establish a wireless connection usingwireless local area network (WLAN) technology (step 132). As such, avoice connection can be established from the caller to the mobileterminal 12 (step 134).

Assume at some point that the mobile terminal 12 begins moving out ofthe terminal adaptor zone 24 (step 136). Upon detecting this condition,the mobile terminal 12 will initiate registration with the cellularaccess network 20 by sending a registration message to the wirelessswitch 18 via the cellular access network 20 (step 138). Generally, theregistration message will identify the mobile terminal 12 using a MobileIdentification Number (MIN) or the like. Upon receiving the registrationmessage from the mobile terminal 12, the wireless switch 18 will send aRegistration Notification (REGNOT) message identifying the mobileterminal 12 to the VLR 32 (step 140), which will forward the REGNOTmessage to the HLR 34 (step 142) to obtain the user's profileinformation, which essentially identifies the services and access towhich the mobile terminal 12 is entitled. Accordingly, the HLR 34 willsend a REGNOT response back to the VLR 32 providing the user profileinformation and associated MIN (step 144). The VLR 32 will forward theREGNOT response to the wireless switch 18 (step 146), which will send aRegistration Acknowledgement (ACK) to the mobile terminal 12 (step 148)to let the mobile terminal 12 know that it has been successfullyregistered.

At some point when the mobile terminal 12 is leaving the terminaladaptor zone 24, the mobile terminal 12 may detect a weak signal thatfalls below a defined threshold, or simply detect a user request totransfer from the terminal adaptor 16 to the cellular access network 20,and send an appropriate message to the terminal adaptor 16 (step 150).The terminal adaptor 16, upon receiving the signal from the mobileterminal 12 or as it detects loss of communication with the mobileterminal 12, may send a SIP Notify message to the service node 30 toinitiate the transfer. Preferably, the SIP Notify message will identifythe directory number DN1 associated with the mobile terminal 12, as wellas the type of transfer, in this case, a request to facilitate a handofffrom the WLAN access to cellular access for the mobile terminal 12 (step152). In response, the service node 30 will send a Location Request(LOCREQ) message including the directory number DN1 to the HLR 34 (step154). The HLR 34 will respond by sending a Route Request (ROUTREQ)message for the MIN associated with the directory number DN1 to the VLR32 (step 156), which will forward the ROUTREQ message to the wirelessswitch 18 to obtain the temporary directory number for the mobileterminal 12 (step 158).

The temporary directory number is associated with the registration forthe mobile terminal 12. Accordingly, the wireless switch 18 will findthe temporary directory number or provide the temporary directory numberassociated with the MIN and respond with a ROUTREQ response includingthe temporary directory number to the VLR 32 (step 160), which willforward the ROUTREQ response with the temporary directory number to theHLR 34 (step 162). The HLR 34 will respond to the original LOCREQmessage by sending a LOCREQ response with the temporary directory numberto the service node 30 (step 164). The service node 30 will then send aSIP Notify message identifying the temporary directory number and thedirectory number DN1 to the terminal adaptor 16 (step 166). The terminaladaptor 16 will send a message to request a call transfer for the callin progress to the temporary directory number (step 168). The wirelineswitch 14 will then place the call on hold (step 170) and initiate aconnection through the wireless switch 18. The connection may beestablished by sending an ISUP IAM message identifying the caller (DN0)and the called party (TDN) to the wireless switch 18 (step 172). Thewireless switch 18 will then initiate ringing of the mobile terminal 12through the cellular access network 20 (step 174). The wireless switch18 will also send an ISUP ACM back to the wireline switch 14 (step 176),which will forward the ISUP ACM back through the PSTN 22 toward thecaller's telephony switch (step 178).

Once the mobile terminal 12 is answered (step 180), the wireless switch18 will send an ISUP ANM back to the wireline switch 14 (step 182),which will forward the ISUP ANM back through the PSTN 22 (step 184). Atthis point, the wireline switch 14 will drop the initial connection viathe terminal adaptor 16 (step 186) and establish a TDM connection withthe caller's telephony switch (step 188). The wireline switch 14 willconnect the original incoming call to the wireless switch 18 (step 190)over a TDM connection between the wireline switch 14 and the wirelessswitch 18 (step 192). A wireless connection is facilitated between thewireless switch 18 and the mobile terminal 12 via the cellular accessnetwork 20 (step 194). At this point, a voice connection is establishedbetween the mobile terminal 12 and the calling party (step 196), and thetransfer is complete.

Once the call has ended, the mobile terminal 12 will send an Onhooksignal to the wireless switch 18 (step 198), which will send an ISUPRelease (REL) message back to the wireline switch 14 (step 200), whichwill forward it back through the PSTN 22 toward the caller's telephonyswitch (step 202) to tear down the connections necessary for the call.Although an exemplary embodiment is illustrated, those skilled in theart will recognize that the call transfer and registration initiationmay be controlled or initiated by the terminal adaptor 16 or the mobileterminal 12, and that these entities may communicate with each other asnecessary to effect such functionality.

Notably, signaling between the terminal adaptor 16 and the wirelineswitch 14 may be facilitated over the telephone line or via the datanetwork 28, directly or through the service node 30. The manner in whichsignaling is provided to the wireline switch 14 is very flexible.Further, the mechanism with which to establish the second connection viathe wireless network 14 in effecting the transition is also flexible.For example, if the telephone line is an ISDN Basic Rate Interface (BRI)line, the signaling channel associated with BRI line can be used totransmit the call transfer information to the wireline switch 14.

A block representation of the terminal adaptor 16 is provided in FIG. 3.Preferably, the terminal adaptor 16 will include a control system 38operatively associated with a local wireless interface 40, one or moretelephony line interfaces 42, an Ethernet interface 44, and a signalprocessing function 46. The signal processing function 46 is part of thecontrol system 38, and is capable of providing all the necessary coding,decoding, and conversions necessary for either of the telephony lineinterface 42 and Ethernet interface 44 to operate with the localwireless interface 40. The local wireless interface 40 is associatedwith an antenna 45, and is configured to communicate wirelessly with themobile terminal 12 using any applicable wireless technology, such astraditional analog or digital cordless technology, wireless local areanetwork technology including 802.11-based technologies, and Bluetoothtechnology.

Clearly, the mobile terminal 12 must be equipped with a compatibleinterface and be configured to cooperate with the terminal adaptor 16 tofacilitate normal telephone operation. As such, the terminal adaptor 16and the mobile terminal 12 must cooperate such that the mobile terminal12 knows when to ring, the terminal adaptor 16 knows when the mobileterminal 12 has been answered or ends a call, and the mobile terminal 12receives any caller identification or like messaging intended for theuser or necessary by the mobile terminal 12 for operation. Further, thelocal wireless interface 40, alone or in conjunction with the controlsystem 38, must be able to periodically or continuously detect whetherthe mobile terminal 12 is within communication range, and thus withinthe terminal adapter zone 24. Those skilled in the art will recognizenumerous techniques for the mobile terminal 12 and terminal adaptor 16to cooperate with one another to determine whether or not communicationsare possible.

Turning now to FIG. 4, a block diagram of a service node 30 isillustrated. The service node 30 will preferably include a controlsystem 48 having sufficient memory 50 to store the software 52 necessaryfor operation as described above. The control system 48 is alsoassociated with one or more packet interfaces 54 to facilitatecommunications with the terminal adaptor 28 via the data network 16, aswell as directly or indirectly with the wireline switch 14.

The basic architecture of the mobile terminal 12 is represented in FIG.5 and may include a receiver front end 56, a radio frequency transmittersection 58, an antenna 60, a duplexer or switch 62, a baseband processor64, a control system 66, a frequency synthesizer 68, and an interface70. The receiver front end 56 receives information bearing radiofrequency signals from one or more remote transmitters provided by abase station. A low noise amplifier 72 amplifies the signal. A filtercircuit 74 minimizes broadband interference in the received signal,while downconversion and digitization circuitry 76 downconverts thefiltered, received signal to an intermediate or baseband frequencysignal, which is then digitized into one or more digital streams. Thereceiver front end 56 typically uses one or more mixing frequenciesgenerated by the frequency synthesizer 68. The baseband processor 64processes the digitized received signal to extract the information ordata bits conveyed in the received signal. This processing typicallycomprises demodulation, decoding, and error correction operations. Assuch, the baseband processor 64 is generally implemented in one or moredigital signal processors (DSPs).

On the transmit side, the baseband processor 64 receives digitized data,which may represent voice, data, or control information, from thecontrol system 66, which it encodes for transmission. The encoded datais output to the transmitter 58, where it is used by a modulator 78 tomodulate a carrier signal that is at a desired transmit frequency. Poweramplifier circuitry 80 amplifies the modulated carrier signal to a levelappropriate for transmission, and delivers the amplified and modulatedcarrier signal to the antenna 60 through the duplexer or switch 62.

As noted above, the mobile terminal 12 must be able to communicate withthe terminal adaptor 16 as well as with the cellular access network 20.Accordingly, the receiver front end 56, baseband processor 64, and radiofrequency transmitter section 58 cooperate to provide either a cellularinterface for the wireless access network 20 and the local wirelessinterface 40 for the terminal adaptor 16. These functions may beimplemented using redundant circuitry, or by configuring commoncircuitry to operate in different modes. The configuration of the mobileterminal 12 will be dictated by economics and designer choice. Themobile terminal 12 is configured such that if the local wirelessinterface 40 is not functional, communications are switched to thewireless network interface. Alternatively, the mobile terminal 12 couldhave both the local wireless interface 40 and the wireless networkinterface in operation at the same time and select one of the two forcommunication at any given time based on signal quality, registration,or other factors.

A user may interact with the mobile terminal 12 via the interface 70,which may include interface circuitry 82 associated with a microphone84, a speaker 86, a keypad 88, and a display 90. The interface circuitry82 typically includes analog-to-digital converters, digital-to-analogconverters, amplifiers, and the like. Additionally, it may include avoice encoder/decoder, in which case it may communicate directly withthe baseband processor 64. The microphone 84 will typically convertaudio input, such as the user's voice, into an electrical signal, whichis then digitized and passed directly or indirectly to the basebandprocessor 64. Audio information encoded in the received signal isrecovered by the baseband processor 64, and converted by the interfacecircuitry 82 into an analog signal suitable for driving the speaker 86.The keypad 88 and display 90 enable the user to interact with the mobileterminal 12, input numbers to be dialed, address book information, orthe like, as well as monitor call progress information.

Those skilled in the art will recognize improvements and modificationsto the preferred embodiments of the present invention. All suchimprovements and modifications are considered within the scope of theconcepts disclosed herein and the claims that follow.

1. A method for transitioning communications with a mobile terminal froma wireline network to a wireless network, wherein the mobile terminal isprovided with a primary directory number associated with the wirelinenetwork, the method comprising: a) receiving a request for a temporarydirectory number, which has been temporarily assigned to the mobileterminal by the wireless network; b) accessing the temporary directorynumber; and c) providing the temporary directory number to allow awireless connection to be established with the mobile terminal via thewireless network.
 2. The method of claim 1 wherein an initial connectionfor a call is established through the wireline network via a terminaladaptor.
 3. The method of claim 2 wherein the request is received fromthe terminal adaptor and the temporary directory number is provided tothe terminal adaptor.
 4. The method of claim 3 wherein the terminaladaptor initiates establishment of the wireless connection and transferof communications from the wireline connection to the wirelessconnection.
 5. The method of claim 4 wherein the terminal adaptor iscoupled to a wireline switch in the wireline network and the terminaladaptor initiates establishment of the wireless connection by sending arequest to the wireline switch to establish a connection to the mobileterminal via the wireless network using the temporary directory numberand wherein the transfer of communications from the wireline connectionto the wireless connection is effected by the wireline switch.
 6. Themethod of claim 1 wherein the temporary directory number is accessedfrom the wireless network.
 7. The method of claim 6 wherein thetemporary directory number is accessed via a home location registerassociated with the wireline network.
 8. The method of claim 7 whereinthe home location register accesses the temporary directory number froma visiting location register associated with the wireless network. 9.The method of claim 8 wherein the visiting location register accessesthe temporary directory number from a wireless switch, which facilitatesthe wireless connection with the mobile terminal.
 10. The method ofclaim 2 wherein the mobile terminal registers with the wireless networkwhile being served by the wireline network.
 11. The method of claim 10wherein the mobile terminal registers with the wireless network while aconnection is established via the wireline network.
 12. The method ofclaim 10 wherein the mobile terminal registers with the wireless networkprior to a connection being established via the wireline network. 13.The method of claim 10 wherein the mobile terminal registers with thewireless network prior to transitioning to the wireless connection. 14.The method of claim 1 further comprising: a) establishing a wirelineconnection via the wireline network; b) establishing the wirelessconnection via the wireless network; and c) transferring communicationswith the mobile terminal from the wireline connection to the wirelessconnection.
 15. A system for transitioning communications with a mobileterminal from a wireline network to a wireless network, wherein themobile terminal is provided with a primary directory number associatedwith the wireline network, the system comprising: a) a communicationinterface; and b) a control system associated with the communicationinterface and adapted to: i) receive a request for a temporary directorynumber, which has been temporarily assigned to the mobile terminal bythe wireless network; ii) retrieve the temporary directory number; andiii) provide the temporary directory number to allow a wirelessconnection to be established with the mobile terminal via the wirelessnetwork.
 16. The system of claim 15 wherein an initial connection for acall is established through the wireline network via a terminal adaptor.17. The system of claim 16 wherein the request is received from theterminal adaptor and the temporary directory number is provided to theterminal adaptor.
 18. The system of claim 17 wherein the terminaladaptor initiates establishment of the wireless connection and transferof communications from the wireline connection to the wirelessconnection.
 19. The system of claim 18 wherein the terminal adaptor iscoupled to a wireline switch in the wireline network and the terminaladaptor initiates establishment of the wireless connection by sending arequest to the wireline switch to establish a connection to the mobileterminal via the wireless network using the temporary directory numberand wherein the transfer of communications from the wireline connectionto the wireless connection is effected by the wireline switch.
 20. Thesystem of claim 15 wherein the temporary directory number is accessedfrom the wireless network.
 21. The system of claim 20 wherein thetemporary directory number is accessed via a home location registerassociated with the wireline network.
 22. The system of claim 21 whereinthe home location register accesses the temporary directory number froma visiting location register associated with the wireless network. 23.The system of claim 22 wherein the visiting location register accessesthe temporary directory number from a wireless switch, which facilitatesthe wireless connection with the mobile terminal.
 24. The system ofclaim 16 wherein the mobile terminal registers with the wireless networkwhile being served by the wireline network and the temporary directorynumber is generated in response to the mobile terminal registering withthe wireless network.
 25. The system of claim 24 wherein the mobileterminal registers with the wireless network while a connection isestablished via the wireline network.
 26. The system of claim 24 whereinthe mobile terminal registers with the wireless network while prior to aconnection being established via the wireline network.
 27. The system ofclaim 24 wherein the mobile terminal registers with the wireless networkprior to transitioning to the wireless connection.
 28. The system ofclaim 15 further comprising a wireline switch adapted to: a) establish awireline connection with the terminal adapter; b) initiate a call to themobile terminal using the temporary directory number to establish thewireless connection via the wireless network; and c) transfercommunications with the mobile terminal from the wireline connection tothe wireless connection.